The present invention relates to an optical pickup for use in recording on and/or reproduction from optical discs, such as CD (Compact Disc) and DVD (Digital Versatile Disc) and a method of producing such an optical pickup. Particularly, this invention relates to an optical pickup equipped with a skew adjustment mechanism and a method of producing such an optical pickup.
An optical pickup, installed in optical disc apparatuses and reciprocally movable in the radial direction of an optical disc, is mainly constituted by an optical base and an actuator mounted on the optical base.
The actuator is constituted by an actuator base, a movable unit movably supported by the actuator base through suspension wires, and an objective lens attached to the movable unit.
An assembly procedure for such an optical pickup usually includes radial- and tangential-skew adjustments for the attitude (optical axis) of the objective lens to the optical base. Practically, the skew adjustments adjust the attitude of the actuator base to the optical base in tangential and radial directions, which is disclosed, for example, in Japanese Unexamined Patent Publication (JUPP) No. 2000-293873.
An improved skew adjustment mechanism is disclosed, for example, in JUPP No. 2001-23207. The skew adjustment mechanism is provided with a yoke base, a portion of which is bent in an optical base side as an abutting piece. The abutting piece is made to have contact with an opening peripheral edge of a concavity of the optical base for smooth skew adjustments.
In known optical pickups, a yoke base is provided between an optical base and a movable unit, or a yoke is provided at the optical base side with respect to the movable unit, which makes the movable unit to be exposed to an optical disc side in an optical disc apparatus.
Such a structure requires a protective cover to protect the movable unit by covering the most part of the movable unit against adverse effects of dust and foreign bodies, and against damages during the shipment of optical pickups. An optical pickup with such a protective cover is disclosed, for example, in JUPP No. 2005-18864.
Also, in the skew adjustment mechanism disclosed in JUPP No. 2001-23207, the yoke base is provided between the optical base and the movable unit. The movable unit is then inevitably exposed to an optical disc side in an optical disc apparatus, thus requiring such a protective cover.
Nevertheless, an optical pickup equipped with such a protective cover does not meet strong demands for higher cost performance, which require an optical pickup having a movable unit protectable without such a protective cover, equipped with a skew adjustment mechanism with a smaller number of components and a smaller number of adjustment processes, and a method of producing such an optical pickup.